WO2000001767A1

WO2000001767A1 - Pre-applied threadlocker/threadsealant with improved shelf-life

Info

Publication number: WO2000001767A1
Application number: PCT/US1999/015150
Authority: WO
Inventors: James Houlihan; Peter J. Wrobel
Original assignee: Loctite (R&D) Limited
Priority date: 1998-07-02
Filing date: 1999-07-02
Publication date: 2000-01-13
Also published as: AU4968799A

Abstract

An anaerobically curable composition useful as a preapplied threadlocker or sealant composition is disclosed. This composition is an aqueous emulsion or dispersion of (a) at least one (meth)acrylic polymerizable monomer present in amounts of about 4 %-15 % by weight of the total composition; (b) a water-soluble or dispersable binder; and (c) an effective amount of a free-radial initiator isolated in the emulsion or dispersion from the polymerizable monomer. Methods of preparation and articles coated with such compositions are also provided.

Description

PRE-APPLIED THREADLOCKER/THREADSEALANT WITH IMPROVED SHELF-LIFE

FIELD OF THE INVENTION:

The present invention relates to an adhesive composition useful for threadlocking and

sealant applications. More particularly, the present invention is especially suitable for use as

a pre-applied, on-part-stable threadlocking composition for extremely catalytic metallic

substrates such as brass and copper, which are known to accelerate the cure speed of

anaerobic adhesive compositions.

BACKGROUND OF RELATED TECHNOLOGY:

Adhesive compositions useful as threadlockers, such as for nut and bolt assemblies

and the like, are well-known. Anaerobic adhesives have long been known to be especially

useful in preventing such threaded assemblies from loosening by filling up the interstitial

space between the mating threads of a nut and a bolt. These compositions have generally

been applied in liquid form at the time of mating of the parts.

Pre-applied threadlocking compositions are also well-known in the art. Such

compositions are designed to be applied to a threaded part, which can then be stored for later

use. Early preapplied threadlocking compositions consisted of a dry-to-the-touch film which

was skinned-over a flowable or gel-like unreacted monomer. Threading of mating parts

having the pre-applied composition therebetween ruptured the skin and subsequently cured

underlying reactive monomer. These compositions, however, were subject to premature

rupturing of the skin which housed the reactive monomer. Coated nuts and bolts and other threaded assemblies are often stored in large bins, one on top of the other, and consequently

are subjected to the weight and sharp angles of adjacent parts, all of which can rupture the

skinned-over monomer, causing it to ooze. The result is a loss of usable threaded assemblies.

Dry-to-the-touch latex emulsions have been used to carry microencapsulated

monomers and/or initiators and catalysts. For example, U.S. Patent No. 4,417,028 describes

a co-reactive system including a polymerizable monomer, an initiator, a polymerization

accelerator and a binder. The initiator is described as a peroxide microencapsulated initiator.

This patent describes ethoxylated Bisphenol A dimethacrylate in amounts of about 35-40%

by weight. The composition is an aqueous dispersion of the polymerizable components and

the binder and initiator. The binder system is an anhydride copolymer. These compositions

are generally formulated for high strength applications, such as those requiring high break

and prevail torque.

Other threadlocking formulations which include reactive monomer compositions and

a polymerization initiator are described in U.S. Patent No. 5,397,812. This patent discloses a

threadlocker composition in which the reactive monomer, the initiator and activator are

encapsulated and dispersed in a binder. The binder comprises a photocurable resin

composition. The binder may also include a photoinitiator for curing via suitable radiation.

These compositions require hardening of the binder on a part using photoradiation, followed

by breaking of the microcapsules during threading of the parts. These compositions are also

designed for relatively high strength applications. Some threadlocking compositions have focused on using photocurable (meth)acrylate

containing monomers to fix or partially cure the composition on the threaded part. The final

or secondary cure then follows once the part is mated with a complimentary threaded part.

For example, certain patents discuss pre-applied silicone threadlocking compositions,

whereby reactive silicone (meth)acrylate compounds are emulsified in aqueous medium and

applied to parts. U.S. Patent No. 5,635,546 describes a pre-applied silicone threadlocking

composition which includes a reactive silicone (meth)acrylate emulsified in aqueous medium

and a microencapsulated peroxy initiator. The dual curing silicone (meth)acrylate monomer

cures both anaerobically as well as through photoradiation. Amounts of curable monomers

disclosed as useful range from about 30-90% by weight (dry) of the composition.

Additionally, a nonsilicone (meth)acrylate monomer is also optionally combined with the

silicone (meth)acrylate composition. These resins are also designed to provide relatively high

strength break and prevail torques on threaded parts.

To date, threadlocking compositions have been designed for general use on metal

parts. It is known, however, that certain metals such as brass and copper are considered "hot"

due to their high catalytic affect on the curing of anaerobic monomers, while other metals

such as stainless, cadmium and zinc are considered "slow" or substantially non-accelerating

substrates. Known anaerobically curable liquid and preapplied threadlockers cure faster on

these "hot" metals then on such surfaces as stainless steel, cadmium or zinc. The on-part life

(shelf- life) of known anaerobic threadlocking and adhesive compositions are greatly

shortened due to the tendency of the "hot" brass or copper surface to catalyze prematurely the

reactive monomer. This results in a pre-applied threadlocking assembly which is instable and commercially unacceptable. Such threadlocking compositions cannot be pre-applied to brass

or copper surfaces and commercially stored for any significant time period even at room

temperature without experiencing a certain amount of procure. This problem is worsened at

higher temperatures, such as those experienced in warehouse or manufacturing facilities.

Additionally, known preapplied anaerobic threadlocking and sealing compositions

have traditionally been designed to be used to impart relatively high break and prevail torques

once the mating threaded parts are assembled and cured. High break and prevail torques may

be useful in many applications where an assembly is not intended to be frequently

disassembled, but are problematic when low torque applications are required, for example,

when frequent disassembly is desired. For example, pneumatic assemblies on trucks and

automobiles require relatively frequent disassembly for maintenance or repairs. Such

applications require excellent sealing capability between the threaded fittings, but low

adhesive break and prevail torques.

One method of addressing this problem using known preapplied compositions is to

lower the amount of the preapplied composition present on the part. Such a method is

impracticle because it requires tailoring the amount of monomer covering the surface of a part

for each different application, thereby defeating the ability to standardize a composition for

industry-wide application.

Commercial anaerobic preapplied threadlocking compositions sold under the brand

name Loctite Dri-Loc-200 and Dri-Loc-205 are representative of conventional high strength compositions and which exhibit on-part shelf-life in stability on "hot" substrates such as

brass, copper and the like. These compositions contain reactive monomers in the range of 35-

37%o weight and while widely used in the industry for many applications, are not desirable for

use on low strength, high sealing applications and particularly on applications where brass,

copper or other highly active metal catalytic surfaces are present.

The present invention seeks to overcome the disadvantages of the prior art

threadlocking compositions on highly catalytic surfaces such as brass and copper. The

present invention is designed to overcome the instability problems associated with the prior

art compositions and allows for a pre-applied threadlocking composition which exhibits

significantly greater on-part life then the aforementioned compositions. Moreover, the

compositions are designed to be low strength, high sealing compositions which can be used

as preapplied, dry-to-the touch threadlockers in applications requiring ease of disassembly of

parts.

Other objects and advantages of the invention will be more fully apparent from the

ensuing disclosure and appended claims.

SUMMARY OF THE INVENTION:

In one aspect, the present invention provides an anaerobically curable composition

useful as a preapplied threadlocker or sealant composition comprising an aqueous emulsion

or dispersion of: (a) at least one (meth)acrylic polymerizable monomer present in amounts of

about 4%o to about 15% by weight; (b) a water-soluble or dispersible binder, and (c) an effective amount of a free, radical initiator isolated in said emulsion or dispersion from said

polymerizable monomer. Mono- and multi-functional (meth)acrylate monomers are useful.

Di(meth)acrylate monomers have been found to be particularly useful. Combinations of

monomers are contemplated so long as their combined weight product is in the

aforementioned range. It has been discovered that amounts of reactive (mefh)acrylate

monomers outside this range do not exhibit the stability on brass and copper surfaces.

The binder may be selected from a wide range of materials but is most desirably an

acrylic latex binder, but may be chosen from a wide variety of materials, its primary purpose

being to serve as a carrier matrix for applying and afixing the reactive monomer system to the

part. The free-radical initiator is most desirably a microencapsulated peroxy compound, but

may also be selected from a wide variety of free radical generators.

In another aspect, the present invention provides a brass or copper surfaced article,

coated with a film formed by evaporation of water from an adhesive composition, said

composition comprising an emulsion or dispersion in water of: (a) at least one polymerizable

(meth)acrylic monomer present in amounts of about 4 to about 15%o by weight; (b) a water-

soluble or dispersible binder; and (c) a microencapsulated free-radical initiator present in an

amount effective to initiate cure of said monomer. BRIEF DESCRIPTION OF THE DRAWINGS:

Figure 1 is a graphic representation of the results of precure testing performed at room

temperature on the commercially available threadlocker sold under the brand name Loctite

Dri-Loc 200. This figure graphically plots the averages of certain data compiled in Table II.

Figure 2 is a graphic representation of the results of precure testing performed at

accelerated aging temperature on the commercially available threadlocker sold under the

brand name Loctite Dri-Loc 200. This figure also graphically plots the averages of certain

data compiled in Table II.

Figure 3 is a graphic representation of the results of precure testing performed at room

Dri-Loc 205. This figure graphically plots the averages of certain data compiled in Table II.

Figure 4 is a graphic representation of the results of precure testing performed at

accelerated aging temperatures on the commercially available threadlocker sold under the

brand name Loctite Dri-Loc 205. The figure graphically plots the averages of certain data

compiled in Table II.

Figure 5 is a graphic representation of the results of precure testing performed at room

temperature on the inventive adhesive composition. This figure graphically plots the average

of certain data compiled in Table III. Figure 6 is a graphic representation of the results of precure testing performed at

accelerated aging temperature on the inventive adhesive composition. This figure graphically

plots the averages of certain data compiled in Table III.

DETAILED DESCRIPTION OF THE INVENTION:

The polymerizable monomers useful in the present invention include a wide variety of

poly- and mono- functional (meth)acrylate esters. One class of polymerizable monomers is

the poly- and mono- functional acrylate and (mefh)acrylate esters having the general structure

CH₂=C(R)COOR, where R is H, CH₃, C₂H₅ or Cl, and R¹ is C,_.g mono- or bicylcoalkyl, a 3 to

8-membered heterocyclic radial with a maximum of two oxygen atoms in the ring, H, alkyl,

hydroxyalkyl or aminoalkyl where the alkyl portion is C _g straight or branched carbon atom

chain.

Among other desirable polymerizable monomers useful in the present invention

include those which fall within the structure:

where R² may be selected from hydrogen, alkyl of 1 to about 4 carbon atoms,

hydroxyalkyl of 1 to about 4 carbon atoms or O

II — H₂C — O— C — C=CH₂

I

R3

R³ may be selected from hydrogen, halogen, and alkyl of 1 to about 4 carbon atoms

and Cj.g mono- or bicycloalkyl, a 3 to 8 membered heterocyclic radical with a maximum of 2

oxygen atoms in the ring;

R⁴ may be selected from hydrogen, hydroxy and

m is an integer equal to at least 1, e.g., from 1 to about 8 or higher, for instance from 1

to about 4;

n is an integer equal to at least 1, e.g., 1 to about 20 or more; and

v is 0 or 1.

Other desirable acrylate ester monomers are those selected from the class of urethane

acrylates conforming to the general structure:

(CH₂ = CR⁵.CO.O.R⁶.O.CO.NH-)₂R⁷ wherein R⁵ is H, CH₃, C₂H₅ or Cl; R⁶ is (i) a C,.₈ hydroxyalkylene or aminoalkylene group, (ii)

a C,.₆ alklamino-C,.₈ alkylene, a hydroxyphenylene, aminophenylene, hydroxynaphthylene or

amino-naphthalene optionally substituted by a C,.₃ alkyl, C,.₃ alkylamino or di- .₃

alkylamino group; and R⁷ is C₂.₂₀ alkylene, alkenylene or cycloalkylene, C₆.₄₀ arylene,

alkarylene, aralkarylene, alkyloxyalkylene or aryloxyarylene optionally substituted by 1-4

halogen atoms or by 1-3 amino or mono- or di- ._j alkylamino or C_1-3 alkoxy groups; or said

acrylates having the general formula;

(CH₂ = CR⁵.CO.O.R⁶.O.CO.NH.R⁷.NH.CO.X-)_nR⁸

wherein R⁵, R⁶, and R⁷ have the meanings given above; R⁸ is the non- functional residue of a

polyamine or a polhydric alcohol having at least n primary or secondary amino or hydroxy

groups respectively; X is O or NR⁹ where R⁹ is H or a C ₇ alkyl group; and n is an integer

from 2 to 20.

Among the specific monofunctional polymerizable acrylate ester monomers

particularly desirable, and which correspond to certain of the structures above, are

hydroxypropyl methacrylate, 2-hydroxyethyl methacrylate, methyl methacrylate,

tetrahydrofurfuryl methacrylate, cyclohexyl methacrylate, 2- aminopropyl methacrylate and

the corresponding acrylates.

Specific polyfunctional monomers which are desirable include polyethyleneglycol

dimethacrylate and dipropylene glycol dimethacrylate. Other desirable polymerizable acrylate ester monomers useful in the instant invention

are selected from the class consisting of the acrylate, methacrylate and glycidyl methacrylate

esters of Bisphenol A. The most desired among all of the free-radical polymerizable

monomers mentioned is ethoxylated Bisphenol-A-dimethacrylate (EBIPMA).

Mixtures or copolymers of any of the above-mentioned free-radical polymerizable

monomers can be employed.

Polymerizable vinyl monomers may also be optionally incorporated and are

represented by the general structure:

R¹⁰-CH=CH-R¹⁰

where R¹⁰ is alkyl, aryl, alkaryl, aralkyl, alkoxy, alkylene, aryloxy, aryloxyalky, alkoxyaryl,

aralkylene, -OO=C-R', where R^! is defined above, can also be effectively employed in the

instant composition.

Copolymers or mixtures of monomers disclosed herein with other compatible

monomers are also contemplated.

The basic purpose of the binder is to support the monomer and other ingredients,

allowing for easy deposition on a part. It is desirable that the binder not interfere with the polymerization of the monomer. The binder should be at least partially soluble in water and

readily soluble.

Generally, the monomer, along with the accelerator of polymerization, is added to the

binder which is at least partially in aqueous solution. The monomer, together with the

accelerator are dispersed or suspended into small droplets in the binder.

The monomer droplet size must not be too small as to cause poor adhesion and

subsequent peeling, not too big as to be unable to wet the substrate surfaces. Generally, the

dispersed monomer droplets are in the size range of about 50 to about 500 microns and

desirably about 100 to about 200 microns.

Upon application of the adhesive composition to a part, the water in the composition

is allowed to evaporate either at room temperature or under heat supplied by any of the

conventional methods such as induction heat, convection heat, radiant heat, infra-red, or

microwave. The resultant preapplied coating or film is dry to the touch once the water has

been evaporated.

Initiators of free-radical polymerization useful in the instant composition include

peroxides, hydroperoxides, peresters, and peracids. Peroxides are desirable and benzoyl

peroxide is the more desirable. Such initiators are generally present in the adhesive

composition in the amounts of about 0.1 %> to about 10%> by weight of the monomer, and

desirably about 0.1% to about 2.0%> by weight. As previously mentioned, a two-part adhesive composition is desirable, one part composing an encapsulated initiator which is

added to the dispersion prior to application of the adhesive composition to a part.

Commonly known accelerators of polymerization include amines and sulfimides.

Tertiary amines, such as N,N-dimethylparatoluidine, and sulfimides such as 3-oxo-2,3-

dihydrobenz-[d]isothiazole- 1,1 -dioxide, commonly known as saccharin, are particularly

useful. However, the most desired accelerators are organometallic compounds, desirably

organometallic polymers containing a metallocene moiety such as a ferrocene moiety.

Suitable metallocenes in related compositions are disclosed more fully in U.S. Pat. No.

3,855,040 which is incorporated by reference herein. These metallocene compounds, as well

as the accelerators mentioned above, are desirably added to the monomer in amounts of about

0.01%) to about 1.0% by weight of the composition prior to forming the dispersion. Other

metallo-containing materials which are non-polymeric have also been found to be effective at

these levels.

Inhibitors and chelators, well recognized in the art for imparting stability to

polymerizable compositions, are recommended. It is desirable that they be added to the

monomer prior to forming the dispersion or emulsion. Those inhibitors useful in the present

composition are usually selected from the group consisting of hydroquinones, benzoquinones,

naphthoquinones, phenanthraquinones, anthraquinones, and substituted compounds of any of

these. Among the chelators which may be optionally present in the adhesive composition are

the beta-diketones. ethylenediamine tetraacetic acid (EDTA) and the sodium salt of EDTA.

Both the inhibitors and chelators may be effectively employed in levels of about 0.1 to about 1%) by weight of the monomer, without adversely affecting the speed of cure of the

polymerizable adhesive composition.

Thickeners, plasticizers, pigments, dyes, diluents, fillers, and other agents common to

the art can be employed in any reasonable manner to produce desired functional

characteristics, providing they do not significantly interfere with the monomer

polymerization. Inert fillers are present in relatively high amounts as compared to

conventional threadlocking systems. Most desired are fillers which add lubricity and sealing

characteristics to the compositions. Teflon (polytetrafluoroethylene) and polyethylene are

non- limiting examples.

The instant adhesive compositions exhibit a marked improvement over the prior art

with regard to on-part life on brass and copper surfaces.

Additionally, the preapplied adhesive compositions of the instant invention have an

on-part life which exhibits improved resistance to heat aging.

The invention will be more fully understood by the following examples, which are not

intended in any way to restrict the effective scope of the invention.

A desirable method of preparing the instant composition is to slowly mix the binder

into deionized water which has been heated to a temperature of about 90 °C. The binder is mixed until most of it is dissolved and the batch is clear and free from lumps. The batch is

cooled to about 60 °C and the pH adjusted.

The polymeric ferrocene compound is added, followed by 15 minutes of mixing and

the same is done for the inorganic filler. Next the pigment is mixed in and finally the

polymerizable monomer is added and the batch mixed 25 °C until it is uniform and has the

desired dispersion particle size distribution.

EXAMPLES

A composition of the present invention may include the following components:

1) water in the amount of about 25-32%> and desirably in the amount of 28-38%>

2) a film forming binder or matrix material which is an aqueous medium and

forms an aqueous dispersion or emulsion with the reactive monomer and is

present in amount of about 30-40% and desirably in amount of 36-37%>;

3) optional, but desirable, inert fillers such as lubricating thickeners, pigments

and the like, present in amounts of about 16 to about 30%> and desirably in

amounts of 25.5 to about 26.5%;

4) (meth)acrylate monomer such as di (meth) acrylate monomer present in

amounts of about 4 to about 15% and desirably 6 to about 7%>;

5) an optional, but desirable, ferrocene cure accelerator present in amount of

about 0.0005%) and desirably in amounts of up to about 0.01%>;

6) an optional, but desirable, EDTA chelator present in amounts of about 0.2 to

about 1.0% and desirably in amounts of about 0.47 to about 0.57%>; 7) microencapsulated benzoyl peroxide present in amounts of about 3 to about

5%.

Compositions formulated in accordance with the above-described general formula and

more specifically in accordance with Table I below were applied to threaded nuts and bolt.

Due to the large degree of inert fillers and low quantity of reactive monomer, the

threadlocking strength of the resultant preapplied composition is designed to be relatively

low. However, it functions well as a sealant and low strength threadlocker in applications

which require repetitive disassembly. In particular, compositions falling within the general

ranges above, and the specific ranges of Table I were found to be extremely stable on brass

and copper containing surfaces.

Table I shows commercially available threadlocking compositions and the inventive

threadlocking composition. These compositions were tested for on-torque, breakaway and

prevailing torque values. The bolts used were 3/8 - 16 brass bolts and the mating nuts were

certified 3/8 - 16 phos-oil nuts. Testing was performed on a snap-on Torquemeter.

Test specimens were degreased in a naphtha hydrocarbon based cleaner and allowed

to dry. The bolts were then coated with the compositions in Table 1 in a conventional

manner and allowed to dry in an oven at 158 °F for 20 minutes.

The nuts and bolts were assembled at 24, 48, 72, 96,168, 336, 504, 1008 and 5040

hours after coating. Upon assembly, the on-torque was recorded. On-torque is the amount of torque required to assemble the coated bolts to the nuts. This torque reading is indicative of

the stability of the preapplied composition on the substrate. A higher on-torque is indicative

of premature polymerization, i.e. precure, caused by the catalytic affect of the brass substrate,

which generally contains a high quantity of copper, with the reactive polymerizable monomer.

After curing 72 hours at room temperature, the breakaway and maximum prevailing

off-torque (within 360° of break) were recorded. The same tests were repeated subsequent to

storing the coated fasteners at 105°F as a test for accelerated aging and long term storage stability.

As will be noted from Tables II and III, as well as Figures 1-6, the present invention

exhibits increased on-part stability as evidenced by a relatively level on-torque value over

time as compared to the commercially available threadlocking compositions (which are

believed to be the closest prior art to the present invention). On-torque valves which do not

significantly increase with on-part time indicate that the composition is not prematurely

reacting.

While the invention has been described herein in reference to various illustrative

aspects and embodiments, it will be appreciated that the utility of the invention is not thus

limited, but rather is susceptible to numerous variations, modifications, and other

embodiments, and accordingly all such variations, modifications and other embodiments are

therefore contemplated within the spirit and scope of the invention as claimed. TABLE I

COMMERCIALLY AVAILABLE AND INVENTIVE THREADLOCKING/SEALANT COMPOSITIONS

Table II

Precure Testing on Dn-Loc 200 on 3/8-16 brass bolts with P/O nuts (values in Inch-Lbs)

Room Temperature 105 °F

Sample No Time to Assemble On Torgue Breakaway Prevailing On Torgue Breakaway Prevailing

1 24 hrs 0 15 5 5 25 10

2 24 hrs 0 25 15 5 15 5

3 24 hrs 0 35 15 5 20 5

4 2 hrs 0 33 15 5 25 5

5 24 hrs 0 10 5 5 10 10

Average 0 24 11 5 19 7

1 48 hrs 2 10 10 5 20 15

2 48 rs 2 20 20 10 60 30

3 48 hrs 2 30 15 5 25 15

4 48 hrs 2 27 25 6 19 15

5 48 hrs 2 47 15 5 10 10

Average 2 27 17 6 27 17

1 72 hrs 2 30 10 56 35 15

2 72 hrs 2 30 15 43 30 15

3 72 hrs 2 13 10 47 33 20

4 72 hrs 2 15 15 46 30 30

5 72 hrs 2 26 26 44 30 15

Average 2 23 15 47 32 19

1 96 hrs 5 30 30 13 17 10

2 96 hrs 4 30 15 14 25 10

3 96 hrs 2 15 10 51 50 30

4 96 hrs 3 20 10 35 25 10

5 96 hrs 3 10 5 32 20 10

Average 3 21 14 29 27 14

1 168 hrs 2 10 10 45 40 20

2 168 hrs 2 20 10 30 30 15

3 168 hrs 3 30 15 45 60 30

4 168 hrs 3 20 10 30 20 10

5 168 hrs 2 20 10 30 20 10

Average 2 20 11 35 34 17

1 336 hrs 5 40 20 100 125 75

2 336 hrs 5 50 25 150 175 100

3 336 hrs 5 30 15 125 195 100

4 336 hrs 5 35 20 180 210 100

5 336 hrs 5 25 15 150 160 75

Average 5 36 19 141 177 90

1 504 hrs 5 15 15 120 125 125

2 504 hrs 5 40 15 175 125 125

3 504 hrs 5 55 60 75 75 75

4 504 hrs 5 35 15 150 100 100

5 504 hrs 5 20 10 175 100 100

Average 5 33 23 139 105 105

1 1008 hrs 5 20 20

2 1008 hrs 5 20 20

3 1008 hrs 5 30 30

4 1008 hrs 5 30 30

5 1008 hrs 5 20 20

Average 5 24 24

1 5040 hrs 5 50 20

2 5040 hrs 5 40 20

3 5040 hrs 5 50 20

4 5040 hrs 5 30 10

5 5040 hrs 5 30 40

Average 5 40 22 Table II

Precure Testing on Dri-Loc 205 on 3/8-16 brass bolts with P/O nuts (values in Inch-Lbs)

Room Temperature 105 °F

1 24 hrs 0 13 5 61 60 60

2 24 hrs 0 150 25 41 49 40

3 24 hrs 0 26 5 46 55 55

4 24 hrs 0 70 30 52 55 55

5 24 hrs 0 120 40 46 40 40

Average 0 76 21 49 52 50

1 48 hrs 2 150 50 35 50 50

2 48 hrs 2 200 50 35 50 50

3 48 hrs 2 175 50 57 80 80

4 48 hrs 2 180 50 47 60 60

5 48 hrs 2 150 40 37 50 50

Average 2 171 48 42 58 58

1 72 hrs 2 100 50 6 75 75

2 72 hrs 2 225 150 9 50 50

3 72 hrs 2 110 50 9 65 65

4 72 hrs 2 210 150 9 50 50

5 72 hrs 2 100 25 11 40 40

Average 2 149 85 9 56 56

1 96 hrs 2 200 60 40 50 50

2 96 hrs 2 110 25 50 50 50

3 96 hrs 2 150 50 25 30 30

4 96 hrs 2 175 50 60 75 75

5 96 hrs 2 205 100 41 50 50

Average 2 168 57 43 51 51

1 168 hrs 2 100 25 37 50 50

2 168 hrs 2 140 25 42 50 50

3 168 hrs 2 130 30 27 25 25

4 168 hrs 2 160 50 27 25 25

5 168 hrs 2 150 40 60 75 75

Average 2 136 34 39 45 45

1 336 hrs 2 200 100 15 25 25

2 336 hrs 2 150 50 30 25 25

3 336 hrs 2 200 100 45 50 50

4 336 hrs 2 225 150 30 40 40

5 336 hrs 2 200 100 30 30 30

Average 2 195 100 30 34 34

1 504 hrs 5 100 25 25 15 15

2 504 hrs 5 175 100 30 30 30

3 504 hrs 5 200 175 70 50 50

4 504 hrs 5 150 75 35 25 25

5 504 hrs 5 100 75 25 15 15

Average 5 145 90 37 27 27

1 1008 hrs 5 500 200

2 1008 hrs 5 500 200

3 1008 hrs 5 500 100

4 1008 hrs 8 300 150

5 1008 hrs 5 300 150

Average 6 420 160

1 5040 hrs 10 120 30

2 5040 hrs 15 110 20

3 5040 hrs 30 120 20

4 5040 hrs 15 120 30

5 5040 hrs 20 110 20

Average 18 116 24 Table III

Precure Testing on Inventive Composition on 3/8-16 brass bolts with P/O nuts (values in Inch-Lbs)

Room Temperature 105 °F

1 168 hrs 13 45 30 10 21 15

2 168 hrs 10 62 30 11 23 15

3 168 hrs 13 68 40 12 24 15

Average 12 58 33 11 23 15

Sample No Time to Assemble On Torgue Breakaway Prevailing On Torgue Breakaway Prevailing 1 504 hrs 15 70 50 15 20 20

2 504 hrs 15 70 50 15 20 20

3 504 hrs 15 60 40 15 20 20

Average 15 67 47 15 20 20

Sample No Time to Assemble On Torgue Breakaway Prevailing On Torgue Breakaway Prevailing 1 1008 hrs 20 60 30 33 30 30

2 1008 hrs 15 60 30 45 41 30

3 1008 hrs 23 60 30 55 35 30

Average 19 60 30 44 35 30

Claims

WHAT IS CLAIMED IS:

1. An anaerobically curable composition useful as preapplied threadlocker or sealant

composition comprising an aqueous emulsion or dispersion of :

(a) at least one (meth)acrylic polymerizable monomer present in amounts of about

4%o- 15%) by weight of the total composition;

(b) a water-soluble or dispersable binder; and

(c) an effective amount of a free-radial initiator isolated in said emulsion or dispersion

from said polymerizable monomer.

2. The composition of claim 1 wherein said (meth)acrylic monomer is present in

amounts of about 6%-10% by weight.

3. The composition of claim 1 wherein said (mefh)acrylic monomer has the structure:

where G may be hydrogen, halogen or alkyl of 1 to about 4 carbon atoms, and R¹ may be

selected from alkyl, cycloalkyl, alkenyl, cycloalkenyl, alkaryl, aralkyl or aryl groups of about

1 to 16 carbon atoms, any of which may be optionally substituted or interrupted as the case

may be with silane. silicon, oxygen, halogen, carbonyl, hydroxyl, ester, carboxylic acid, urea,

urethane, carbamate. amine, amide, sulfur, sulfonate, sulfone and the like.

99 The composition of claim 1 wherein said acrylic monomer falls within the structure:

O II HoC=C— C— O- ^■(CH₂), m

R3

where R² may be selected from hydrogen, alkyl of 1 to about 4 carbon atoms,

hydroxyalkyl of 1 to about 4 carbon atoms or

O II — H₂C— O— C— C=CH₂

I

R3

and Cj.₈ mono or bicycloalkyl, a 3 to 8 membered heterocyclic radial with a maximum of 2

oxygen atoms in the ring;

R⁴ may be selected from hydrogen, hydroxy and

O II — H₂C— O— C— C =CH₂ I R3

to about 4;

n is an integer equal to at least 1, e.g., 1 to about 20 or more; and v is 0 or 1.

5. The composition of claim 1 wherein the acrylic monomer is selected from a group

consisting of polyethylene glycol di(mefh)acrylates, Bisphenol-A di(mefh)acrylates, such as

ethoxylated Bisphenol-A (meth)acrylate ("EBIPMA"), tetrahydrofurane (mefh)acrylates and

di (meth)acrylates, hydroxypropyl (mefh)acrylate, hexanediol di (mefh)acrylate, trimethylol

propane tri (meth)acrylate.

6. The composition of claim 1 further includes a lubricating thickening agent.

7. The composition of claim 1 further including an anaerobic cure accelerator.

8. The composition of claim 1 further including an additional emulsion for viscosity

modification.

9. A brass or copper article coated with a film formed by evaporation of water from an

adhesive composition, said composition comprising an emulsion or dispersion of:

(a) at least one (meth)acrylic polymerizable monomer present in amounts of about 4%

to about 15%;

(b) a water-soluble or dispersible binder; and

(c) a free-radical isolated in said emulsion or dispersion from said polymerizable

monomer.

10. The article of claim 9 wherein said (meth)acrylic polymerizable monomer is present

in amounts of about 4% to about 15%> by weight of the total composition.

11. The article of claim 9 wherein said (meth)acrylic polymerizable monomer falls with

the structure:

H₂C=CGCO₂R¹

selected from alkyl. cvcloalkyl, alkenyl, cycloalkenyl, alkaryl, aralkyl or aryl groups of about

may be with silane, silicon, oxygen, halogen, carbonyl, hydroxyl, ester, carboxylic acid, urea,

urethane, carbamate, amine, amide, sulfur, sulfonate, sulfone and the like.

12. The article of claim 9 wherein said (meth)acrylic polymerizable monomer falls within

the structure:

where R² may be selected from hydrogen, alkyl of 1 to about 4 carbon atoms,

hydroxyalkyl of 1 to about 4 carbon atoms or -H₂C — O — C — C =CH₂

I

R3

and . mono or bicycloalkyl, a 3 to 8 membered heterocyclic radial with a maximum of 2

oxygen atoms in the ring;

R⁴ may be selected from hydrogen, hydroxy and

O

II

— H₂C — O — C — C =CH₂

I

R3

to about 4;

n is an integer equal to at least 1 , e.g. , 1 to about 20 or more; and

v is 0 or 1.

13. The article of claim 9 wherein said water-soluble or dispersible binder in said film

composition is selected from the group consisting of

14. The article of claim 9 wherein said free-radical initiator of said film composition is a

microencapsulated peroxy compound.

15. The article of claim 9 wherein said film composition further includes an anaerobic

accelerator.

16. The article of claim 9 wherein said film composition further includes as a lubricating

thickening agent.

17. A method of preparing a low strength stable adhesive composition for films to be

stored on brass and copper surfaces comprising the steps of:

(i) providing an adhesive composition in an aqueous emulsion or dispersion of

(a) at least one anaerobic curable (meth)acrylic monomer, wherein said

monomer is present in amounts of about 4 to about 15% by total weight of the

compositions;

(b) a water-soluble or dispersible binder; and

(c) a curingly effective amount of a free-radical initiator;

(ii) applying said composition to said brass or copper surface;

(iii) permitting water to evaporate from said adhesive composition thereby leaving a

polymerizable film said surface. AMENDED CLAIMS

[received by the International Bureau on 16 November 1999 (16.1 1.99); original claim 13 amended; remaining claims unchanged (1 page)]

R³ may be selected from hydrogen, halogen, and alkyl of 1 to about 4 carbon atoms and C,.₈ mono or bicycloalkyl, a 3 to 8 membered heterocyclic radial with a maximum of 2 oxygen atoms in the ring;

R⁴ may be selected from hydrogen, hydroxy and

O II — H₂C— O— C— C=CH₂

R3

5 m is an integer equal to at least 1, e.g., from 1 to about 8 or higher, for instance from 1 to about 4;

« is an integer equal to at least 1, e.g.. 1 to about 20 or more: and v is 0 or 1.

0 13. The article of claim 9 wherein said water-soluble or dispersible binder in said film composition is a latex binder.

14. The article of claim 9 wherein said free-radical initiator of said film composition is a microencapsulated peroxy compound. 5